Shaken Infants Die of Neck Trauma, Not of Brain Trauma

Abstract

Shaken baby syndrome (SBS) is routinely diagnosed on the basis of a classic triad of autopsy findings, namely retinal hemorrhage, subdural hemorrhage, and anoxic encephalopathy. However, ongoing controversy exists regarding the specificity and potential causes of these signs, and hence their reliability as de facto markers of SBS, or of non-accidental head injury, where no external signs of trauma are evident. We investigated the deaths of 35 infants and young children, which fell into two broad groups: those with suspected hyperflexion/extension neck injuries, and those without. At autopsy, the entire cervical spinal column (spinal cord, vertebrae, intervertebral discs, neurovascular structures and adjacent soft tissues) was removed, formalin-fixed, decalcified, dissected, and microscopically evaluated. Of the 12 cases in which hyperflexion/extension was either suspected or confirmed, all had evidence of either bilateral or unilateral hemorrhages within or surrounding the C3, C4, and/or C5 cervical spinal nerve roots. We provide evidence that hyperflexion/extension forces as experienced by shaken and impacted infants and young children lead to injury of the cervical spinal nerve roots that innervate the diaphragm, with resulting asphyxia and hypoxic brain injury. Therefore, we propose that trauma to the third through fifth cervical spinal nerve roots induced by hyperflexion/extension of the neck is the cause of the anoxic encephalopathy of the classic SBS triad, and is therefore not only a more specific indicator of hyperflexion/extension injury than subdural hemorrhage alone, but is the mechanism of injury in these cases.

Development of a Model of Hemispheric Hypodensity (“Big Black Brain”)

“…Although not evaluated in this model, the unilateral pattern of HH is unlikely to result from neck injury and/or nerve reflexes from the dura, which cause global apnea, a mechanism purported by Geddes and colleagues and others. 10,11,[41][42][43] An alternate possible mechanism is a regional metabolic mismatch between supply and demand. The exact pathophysiological mechanisms by which widespread unilateral hemispheric hypoxic-ischemic injury is initiated and propagated in children are not fully understood, but similar findings were produced in this model in the absence of angular acceleration/deceleration.…”

A Retrospective Study of Cervical Spine MRI Findings in Children with Abusive Head Trauma

“…Six of these children had no evidence of impact to the head. In another study on fatal cases, Matshes et al [17] studied 35 children (newborns to 36 months of age) by removing the entire cervical spinal column and completing extensive dissection with microscopic evaluation. Of the 12 cases with hyperflexion/hyperextension (suspected or confirmed), all had bilateral or unilateral hemorrhages within or surrounding C3, C4, and/or C5 cervical spinal nerve roots.…”

The Swedish shaken baby syndrome report and review: what does the latest knowledge tell us?

“…The SBU report is a further addition to previous large‐scale judicial reviews undertaken in the UK (Goldsmith review, 2006) and in Canada (Goudge Inquiry, 2008), which concluded that the presence of the triad alone should not automatically lead to a diagnosis of SBS .…”

“…The topic has never ceased generating heated controversy and acrimonious debates. At the core of the dispute is not whether shaking can cause devastating lethal injury, as it can certainly do . The main controversy resides in the value of the ‘triad’ as categoric evidence of abusive head trauma (AHT) by shaking when no other credible explanations are found.…”